Blood tests are commonly performed tests for prevention or diagnosis of diseases. In most cases, blood tests are performed for serum analysis such as serum biochemistry analysis, serum immunological analysis, serum hormone analysis, serum tumor marker analysis, and serum drug level analysis.
In order to collect serum from blood for serum analysis, blood collection containers such as vacuum blood collection tubes and blood collection tubes have been widely used. Serum is collected as follows: collecting blood in a blood collection container followed by coagulation of the collected blood sample; and centrifuging the blood sample to separate serum and clot according to the specific gravity.
Conventional blood collection containers for collecting blood are made of a glass or a synthetic resin such as polystyrene, polymethyl methacrylate, polyethylene, or polyethylene terephthalate. Blood collection containers made of a glass allow blood to coagulate in a comparatively short time, but still require about 40 to 60 minutes for blood coagulation. In contrast, containers for blood tests made of a synthetic resin require four hours or more for blood coagulation. In order to further reduce the time required for blood to coagulate, blood coagulation promoting agents for promoting blood coagulation have been used.
As is known, blood coagulation is initiated with activation of the blood coagulation factor XII and completed by conversion of fibrinogen to fibrin through a large number of reactions and has a plurality of complex pathways. In Patent Documents 1 to 3, an enzymatic agent (e.g. thrombin or snake venom enzyme) for promoting the conversion reaction of fibrinogen to fibrin at the final stage of blood coagulation is used as a blood coagulation promoting agent for promoting blood coagulation. Use of such an enzymatic agent as a blood coagulation promoting agent allows blood to coagulate within five minutes.